volume-occupancy-based actuated signal control system: design and implementation to diamond interchanges in houston

This paper presents a new volume-occupancy-based actuated signal control system for a diamond interchange, where a two-way arterial street intersects two one-way streets on each side of a freeway, aiming to approximately capture vehicle platoons and thus to improve the traffic by adaptively adjusting the plan. as a sponsored project aiming at immediate implementation, this system had to be designed based on conventional loop detectors and econolite asc/3-2100 controller, which are currently used by the texas department of transportation (txdot). loop detectors placed in the pavement at each approach were used to collect real-time traffic volume and occupancy every 1 min. these data were then aggregated into 15-min flow and 15-min average occupancy, used in the proposed control logic to help vehicle platoons more smoothly passing through a diamond interchange. based on onsite observations and data from loop detectors, it shows that the proposed system works well when the traffic flow is higher than 400 veh/h/ln. for arterial roads in the morning peak hours, the occupancy can be reduced by over 10% with a similar or even higher flow rate. the findings exhibit a low-cost method to improve traffic flow at a diamond interchange by using widely used conventional loop detectors. © 2021, iran university of science and technology.